The present invention relates to an apparatus for producing water having redox activity which can generate an in-vivo redox reaction and an apparatus for producing water having redox activity.
Amidst a world-wide demand for the advent of novel technology on the reduction of emission of CO2 which will be effective in coping with global warming, with respect to water treatment technology, the sterilization of bacteria, the elimination of microorganisms and the decomposition of organic substances in water are mainly carried out by the decomposition using chemicals, a filtering method using a film, sterilization using ultraviolet rays and an oxygen reduction reaction using ozone.
Among these methods, with respect to the ozone method, the use of an ultra-high-concentration ozone method in which ozone concentration is high exceeding 200 ppm has been studied and developed. It is thought that no burden is imposed on the environment due to residual ozone because of instable property of ozone per se. However, due to strong oxidation power of ozone, a cost for applying anti-corrosion countermeasure to piping and processing facilities increases, and anti-corrosion countermeasure such as Teflon coating becomes inevitable in all circuits.
In reality, the residual ozone is present in a stable state in water for several hours, and vaporized ozone continuously affects the environment even after being discharged into the atmosphere. Even ozone of low concentration also directly affects a human body through a respiratory organ trouble or the like. Although the drawback caused by ozone is confused with the acceleration of global warming caused by the destruction of the ozone layer in the stratosphere, ozone is heavier than carbon dioxide and ozone generated on the ground does not reach the stratosphere and remains in the troposphere thus accelerating the global warming.
There has also been a report that the troposphere ozone per se is a gas with a strong greenhouse effect and hence, 20 to 30% of the global warming brought about by the whole greenhouse gas effect is derived from a forced radiation of the troposphere ozone (see non-patent document 1, for example).
Further, according to a recent report, there has been reported a simulation result that when the secondary influence exerted on the vegetation which is expected to absorb carbon dioxide is taken into consideration in addition to the direct greenhouse effect due to ozone, the greenhouse effect derived from the troposphere ozone becomes twice as large as the conventionally expected greenhouse effect (see non-patent document 2, for example).
It has been thought that most of the troposphere ozone is a photochemical oxidant which is generated due to a photochemical reaction between ultraviolet rays in solar beams and nitrogen oxide, carbon hydride or the like discharged from factories or internal combustion engines of automobiles and the like. However, along with the utilization of ozone water in a wide range covering the sterilization in kitchens or the like or the use of ozone water in fish farms and ordinary households, residual ozone discharged and diffused from ozone water is added to the troposphere ozone. This addition of the residual ozone is considered one reason that photochemical smog alarm (the alarm being given when a state where the atmospheric ozone concentration exceeds 0.12 ppm continues for 1 hour) is generated not only in industrial cities and large urban cities but also in local cities and rural areas. Accordingly, there has been a demand for the development of novel technology which can readily dissipate the residual ozone generated by ozone treatment thus reducing a total ozone discharge quantity.
On the other hand, it has been known that active oxygen species which exist in a wide range constantly in nature and in living organisms cause a cell membrane disorder due to their strong oxidation power and have sterilization and antiparasitic ability. The utilization of active oxygen species in an air cleaner or the like has been attracting attentions.
Further, the presence of active oxygen species as a causal substance for cytotoxity which generates carcinogenic activity or angiogenic activity has been confirmed and has also been treated as an in-vivo disorder transmission substance. The characteristic of the active oxygen species is clarified in the course of investigating the cause of the in-vivo disorder. It is found that superoxide dismutase (SOD) and NO. are in charge of the elimination of O2− in the living organism thus maintaining the homeostasis.
Originally, the active oxygen species indicate, in general, oxygen species such as superoxide anion radicals O2−), hydrogen peroxide water (H2O2), hydroxy radicals (.OH), singlet oxygen (1O2), while the active oxygen species indicate, in a broader meaning, lipid peroxide (LOOH, LOO.), halogenation oxygen (ClO−) and, further, nitrogen monoxide radicals (NO.) or organic radical species containing oxygen which is identified as a relaxation factor derived from in-vivo vascular endothelial.
In the broader meaning, although hydrogen peroxide belongs to a category of active oxygen species, hydrogen peroxide clearly differs from other active oxygen species with respect to the points that hydrogen peroxide is an extremely stable compound, can be preserved for a long period at a room temperature, and can be generated at high concentration and the like. However, due to their characteristics of hydrogen peroxide where the concentration of hydrogen peroxide can be easily measured even with a ultra minute quantity in a luminol reaction or the like, for elucidating an oxygen reduction reaction, that is, a redox reaction in an ecological system and a living organism, hydrogen peroxide is incorporated and is used as a stimulus transmission substance for general purpose.
Accordingly, the active oxygen species according to the present invention include singlet oxygen (1O2) and cyclic peroxide and hydroperoxide generated from singlet oxygen in addition to so-called free radicals such as superoxide anion radicals (O2−), hydroxy radicals (.OH), lipid peroxide (LOOH, LOO.), halogenation oxygen (ClO−), nitrogen monoxide radicals (NO.), organic radical species containing oxygen (phenoxy radicals, for example), and do not include hydrogen peroxide.
Further, recently, an in-vitro measurement method and an in-vitro determination technique have been developed, and it has been found that the lifetime of the active oxygen species can be held or operated only for an extremely short time of several milliseconds or less, and it is considered that the constant quantitative generation of the active oxygen species except for hydrogen peroxide is impossible.
It has been clarified that the redox reaction which is an oxygen reduction reaction attributed to these active oxygen species brings about the protein synthesis or synthesis of signal transmission substances through various paths in cells. However, the role of the redox reaction attributed to active oxygen species in nature has not yet been completely clarified.
Activities which develop the redox activity which is an oxygen reduction reaction generated in living organism cells in vitro are collectively referred to as the redox activity of the present invention. Here, as a result of the generation of intracellular redox reaction attributed to the extracellular administration of active oxygen species, the presence or the non-presence of activities is evaluated by confirming the apparent cell death (individual death in case of protozoan) attributed to cell degeneration or an apparent switching signal of a calcium channel existing on a biological membrane.
Further, although it is thought that active oxygen species are contained as part of minus ions, minus ions are substances which are charged with negative electricity among substances charged with slight electricity contained in air. These minus ions also exist in nature and are considered to contribute to equilibrium of an environment. However, there exists an opinion which doubts the identification and quantitative property of these substances which are considered effective at a low level of a femtomolar/L which is 1/1000 of nanomolar/L, and the activity of minus ions on living organisms and the generation and disappearance process of minus ions has not yet been clarified.
On the other hand, free electrons and holes which are generated due to the excitation of a photocatalytic reaction caused by the radiation of light to a photocatalytic body react with water and oxygen so as to generate active oxygen species. However, with respect to a device which verifies and identifies active oxygen species such as super-oxide anion radicals and hydroxy radicals other than an ultra minute quantity of hydrogen peroxide, there is no device other than an active oxygen water producing apparatus at this point of time (see patent document 3, for example). Further, patent document 3 also discloses that super-oxide anion radicals generated by the device appear for a long period of time and the device can produce such water as the water containing active oxygen species and maintains the activity thereof for a long period of time.
Further, a photocatalytic reaction excites a photocatalytic body by radiating ultraviolet rays so that free electrons and holes are generated on a surface of the photocatalytic body, and the photocatalytic body is made of titania. Heretofore, there has been a report where titania powder brings about the decomposition of organic substance by free electrons and holes due to the low-frequency ultrasonic vibrations, and a photocatalytic reaction is generated by sources other than the radiation of ultraviolet rays. Further, it has been reported that the appearance of the hydroxy radicals due to free electrons and holes generated by the radiation of the ultraviolet rays using aluminum oxide powder is confirmed (see patent document 4), for example.
Further, as a water treatment technique which possesses an oxidization force in water and can maintain the activity for a long period of time, there have been known nano-bubbles proposed by National Institute of Advanced Industrial & Technology (see patent document 5, for example). In this technique, by applying physical stimulus to minute bubbles containing oxygen which are contained in an aqueous solution, the bubble diameter of the minute bubbles is sharply shrunken thus manufacturing oxygen nano-bubbles. As a device which can perform the water treatment technique, in a process of sharply shrinking the minute bubbles, by applying strong cavitation energy to bubbles using the ionization decomposition and low-frequency ultrasonic vibrations of 26 kHz, a phisico-chemical change is applied to the minute bubbles.
Further, as a method which enables long-period preservation of fruits and vegetables using atomized water vapor as water containing active oxygen, there has been known a method for long-period preservation of fruits and vegetables proposed by NISSHOKU Corporation (see patent document 6, for example). Here, water containing active oxygen of extremely high concentration of 1 to 10 ppm is atomized as vapor in the atmosphere by a photocatalytic reaction and the electro-chemical reduction of polyaniline which is an electron-donating polymer and hence, the bacteria which adhere to surfaces of fruits and vegetables and stored in a humid refrigerator can be sterilized. However, there is no commercially available device which can carry out this method.
[Non-patent document 1] H. Akimoto and K. Sudo. Climate Sensitivity of Ozone. In: Air pollution and its relations to climate change and sustainable development, 2. Climate change and air pollution. 12-14 Mar., 2007, Gothenburg, Sweden; http://asta.ivl.se/Workshops/[Non-patent document 2] Nature. 2007; Vol. 448, No. 7155: pp. 791-794[Patent document 3] JP-A-2007-116267[Patent document 4] JP-A-2003-112053[Patent document 5] JP-A-2005-246294[Patent document 6] JP-A-2000-157166